Propeller.



PATENTED JULY 18, 1905.

f J. D. PULLERTON.

PROPBLLBR. APPLICATION FILED SBPT.L 1904.

BEST AvALABLE @Op @WMQQ UNITED STATES Patented July 18, 1905.

PATENT OEETSCE.

JOHN D. FULLERTON, OF BOSTON, MASSACHUSETTS.

PROPELLER.

SPECIFICATION forming part of Letters Patent No. 794,932, dated July 18, 1905.

Application tiled September 1, 1904. Serial No. 223,025.

To /n/J, iff/'1,07% it 711.04/ concern:

Be it known that I, JOHN D. FULLERTON, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented an Improvement in Propellers, of which the following description,4 in connection with the accompanying drawings, is a specification, like figures on the drawings representing like parts.

This invention relates to screw-propellers, and has for its object to providea novel form of propeller in which the blades have an increased propelling-surface without materially increasing the overhanging weight back of the bearing.

In most screw-propellers the propeller is hung on the end of the shaft which projects beyond the bearing, and the entire Weight of the propeller thereforecomes on said 'shaft end. The weight of the propeller therefore overhangs the bearing, thus putting the shaft under strain and causing more or less vibration. I overcome this difficulty in my improved construction and also gain the added propellingsurface on the blades by extending the hub of the propeller forwardly over the bearing and also extending the blades forwardly to the frontedge of the hub extension, so that part of the blades overlie the bearings. By extending the blades forwardly over the bearings I ob-` tain a blade with a wide' base and can therefore make the blade comparatively thin without reducing its strength. and at the same time part of the weight of the propelleris carried over the bearing, thus reducing or eliminating the overhanging weight.

Referring to the drawings, Figu-re 1 isa rear View of my improved propeller. Fig. 2 is a section on the line n; ai, Fig. 1. Fig. 3 is a section on the line y y, Fig. 2. Fig. 4 is a detail hereinafter referred to.

The propeller-shaft is designated by 3, and it projects through the hull of the vessel, as usual, and has the propeller 4 fastened onto the end thereof in some suitable way. The bearing for the shaft is designated by 8. and it is located outside the hull. The propeller is made with a central hub 5, from which two or three blades G extend. Said hub has a larger diameter than the bearing S and is w l 'blades extending to the front edge of the extension 7, as shown in the drawings. The front portion of the blades therefore overlies and extends over the bearing 8. The front Y edge of the blades slants backwardly in the direction of the propeller-shaft, thus making 'a propeller with an entering edge which cuts through the water somewhatA similar to the tail of a fish. A propeller having this shape is less liable to become injured by striking a partly-submerged or floating obstacle than a propeller of ordinary construction. YBy carrying the entrance edge of the blade forwardly over the bearing, as shown, the width of the blade is increased, so that a much thinner 7o blade may beused than in propeller-s of ordinary construction. Furthermore, part of the weight of the propeller is located directly over the bearing, and thus the amount of the weight which overhangs the bearing is either eliminated or very much reduced. This bearing comprises 'a central portion 9, through which the propeller-shaft extends, and an exterior encircling shell 10, said shell being connected to the central portion 9 by a pl'u- 80 rality of radial ribs 11, which greatly strengthens and stiffens the bearing. YVithin the cen-v tral portionv 9 are a plurality of longitudinal wear blocks or strips 12 of lignum-Vitze, which have a direct bearing on a sleeve 13, 35 fast to the propeller-shaft.

I prefer to make the wear-blocks which are below the shaft adjustable in order to take u p wear and for this purpose have provided the central portion S) with adjustable screws 14n, 9 bearing against composition rein force-strips 14: at the back of said wear-blocks, by means of which screws the wear-blocks.may be forced inwardly as wear occurs. These wear-blocks are conlined between a inutking-box 1G and a 9 shoulder l5 at the outer end ol the central portion 9.

The space between the radial ribs 11 in which 'the adjnstilie-screws i4: are located is from the interior of the vessel I air, and thus constitutesa buoyancy-chamber.

Patent, is-

I prefer to provide said casing 21 with an outwardly opening automatically closing valve 22 and to make the propeller-shaftwith the central bore 23, through which air may be forced into the buoyancy-spacerQll within the casing. This construction permits me to pump air into the buoyancy-space. and thus force out any water that may have leaked in.

Since the portions of any propeller-blade which are most etfective in producing useful thrust in the direction of the propeller-shaft are the portions toward the end thereof rather than the portions near the axis of rotation, the eiciency of my propeller is increased rather than diminished by making it with the hub of enlarged size.

I wish it understood that the blades may be secured to the hub in any suitable way-that is, they may be integral with the hub or may be separate pieces made rigid therewith.

Various changes in the construction and arrangement of the parts may be made Without in any way departing from the invention.

Having described my invention, what I claim as new, and desire to secure by Letters 1. In a propeller, a propeller-shaft, a bear- BEST AVAILABLE coP ing therefor, a screw-propeller on the bearing, said propeller having' a hub formed with an extension which overlies and surrounds the bearing, and also having thin blades extending forwardly to the front edge of the hub extension, and having an entrance edge which slants backwardly in the direction of the length of the shaft. l

2. In a propeller mechanism, a propeller'- shaft, a bearing therefor, said bearing including adjustable wear-blocks, and a propeller on said shaft, said propeller having a hub which is recessed to receive the bearing.

3.*In a propeller mechanism, a propellershaft havinga bore therethrough, a propeller thereon, and a hollow case secured to the back side of the propeller and constituting a buoy ancy-space, said casing adapted to be filled with air through the bore of the propellershaft. l

4. In a propeller mechanism, a propellershaft, a propeller thereon, a hollow casing secured to the back side of the propeller and constituting a buoyancy-space, and an automatically-opening valve in said casing, said propeller-shaft having a bore therethrough through. which air may be forced into the buoyancy-space.

In testimony w hereof I have signed my name to this specification in the presence of two subscribing witnesses.

K JOHN D. FULLER"ON.

Witnesses:

LOUIS C. SMITH, MARGARET A. DUNN. 

